Hepatic Stenosis: Definition and Clinical Context
Hepatic stenosis refers to narrowing of the hepatic vessels—either the hepatic veins (hepatic vein stenosis) or the hepatic artery (hepatic artery stenosis)—which can occur as complications of liver disease, vascular disorders, or following liver transplantation.
Hepatic Vein Stenosis
Hepatic vein stenosis represents a partial or segmental narrowing of the hepatic venous outflow tract, which can obstruct the drainage of blood from the liver into the inferior vena cava.
Prevalence and Context
- Partial or segmental stenoses are present in 25-30% of patients with hepatic vein obstruction in Budd-Chiari syndrome 1.
- In patients with IVC obstruction, stenoses occur in approximately 60% of cases 1.
- Hepatic venous stenosis can also occur as a complication in polycystic liver disease, where strategically located hepatic cysts compress the hepatic veins, resulting in hepatic venous outflow obstruction characterized by reduced venous blood drainage from the liver 1.
Clinical Manifestations
- Hepatic venous outflow obstruction from stenosis leads to portal hypertension, ascites, and/or hepatic hydrothorax 1.
- In polycystic liver disease patients scheduled for liver resection, 78% had moderate stenosis of hepatic veins and 22% had severe venous stenosis 1.
Treatment Approach
- Angioplasty or stenting of hepatic vein stenosis can re-establish physiological drainage of portal and sinusoidal blood 1.
- Post-angioplasty re-stenosis is frequent but can be reduced when combined with stent placement 1.
- Primary hepatic vein stenting has become the intervention of choice for hepatic venous outflow obstruction with patency rates exceeding 80% 1.
- Misplacement of a stent may compromise subsequent TIPS or liver transplantation 1.
Important Caveat
Overall, angioplasty/stenting is the definitive treatment for less than 10% of Western Budd-Chiari syndrome patients, though efficacy may be greater in regions with higher prevalence of this specific form 1.
Hepatic Artery Stenosis
Hepatic artery stenosis (HAS) represents narrowing of the hepatic artery, most commonly occurring as a complication after liver transplantation.
Post-Transplant Context
- HAS is defined as any stenosis >70% seen on multidetector CT angiography or digital subtraction angiography 2.
- The prevalence of hepatic artery intervention after liver transplantation is approximately 7.4% 3.
- HAS is thought to predispose patients to biliary complications secondary to ischemic injury, as the bile ducts receive their blood supply exclusively from the hepatic artery 2.
Clinical Significance
- New biliary complications occur in approximately 31% of patients with HAS 2.
- HAS is a significant risk factor for subsequent hepatic artery thrombosis (HAT), which carries a 30-50% risk of liver failure culminating in retransplantation or death 3.
Treatment Considerations
- Endovascular treatment of HAS (with either primary stent placement or percutaneous transluminal angioplasty) can be performed with high technical success (97% primary technical success) 3.
- Primary patency rates after primary stent placement were 92%, 85%, and 69% at 1,3, and 6 months respectively 3.
- In patients with late-onset HAS (≥6 months after transplant) and asymptomatic patients with normal liver function tests, endovascular treatment may not be warranted, as these patients have reduced risk of developing biliary stricture 2.